1. Field of the Invention
This invention relates to a polymer carrier and a method for carrying out scientific, analytical and diagnostic examinations. In particular, this invention relates to a polymer carrier for the rapid detection of pathogenic germs, pathological cell forms and other pathological processes in the human or animal organism.
2. Prior Art
In general and especially in medical laboratory investigations, staining methods are used for the microscopic diagnosis of cells from tissue samples and for the detection of microorganisms. For this purpose, the specimens often must be subjected to very time- and material-consuming reactions, depending on the required degree of differentiation of the intracellular structures and substances to be prepared. For the staining procedure, the necessary stains are dissolved, and the microscopic slides with the sample material to be stained are either immersed in these solutions or coated with the staining solution. The entire staining process often includes several steps of intermediate treatments in different baths. The staining of the sample materials is influenced by various factors, e.g., the type of stain, the reaction time, the pH-value and impurities or precipitates in the staining solution. Many staining solutions tend to precipitate, especially in dilute solution.
The Giemsa solution [e.g., according to L. Hallmann, "Klinische Chemie and Mikrosokopie", Thieme-Verlag (1966)], which is most frequently used in haematology for blood cell examination and detection of pathogenic germs in blood, e.g., trypanosomes or malaria parasites, is very unstable. Such staining solution must be prepared fresh from a parent solution immediately before it is used and must be carefully filtered before the staining process.
Another stain taken into consideration in the examinations underlying this invention is the modified Pappenheim staining method with the purified stains azure B and eosin G, which is recommended especially for staining blood and bone-marrow smears [Wittekind et al., Blut Vol. 32, pp. 70 to 78 (1976)]. Because of the purified stains, such staining method is said to meet the requirements of adequate cell representation better than other panoptic staining methods as, for example, "Giemsa-May-Grunwald". In conventional applications, however, such staining method also has the drawback that the necessary stains must always be prepared fresh immediately before use (the unused excess material being discarded). Furthermore, the staining mixture must be diluted with a buffer solution (pH 6.5) on the specimen to be stained and rinsed off with distilled water after the staining process.
Besides the staining methods described above, others used for diagnostic purposes and scientific examinations also have the drawback that they are time-consuming and complicated. They require constant renewal of the reagents and cannot be standardized in terms of their effect of the specimen.
There are additional methods besides the Giemsa staining method that can be used for the detection of pathogenic germs, e.g., trypanosomes in the blood. With the immunofluorescent method, the germs are specifically identified by means of fluorescent antibodies. A direct and indirect method can be used in immunofluorescent staining. In the direct method the antibody is conjugated with FITC (fluorescein isothiocyanate). Together with the antigen it forms an FITC-antibody-antigen complex. In the indirect method, a fluorochrome-labelled antibody is used which combines with the antigen-antibody complex.
The staining solutions required for the two latter processes, with the antibodies contained in them, also keep only for a limited period of time. They must always be stored in a freezer. Such methods furthermore require great precision in order to ensure the necessary even coating of the specimen with the staining solution.
Not only the staining reactions in medical laboratory examinations, but also other microscopic detection reactions, e.g., in criminology, require complicated time-consuming methods and the use of extreme care.
One method frequently used to detect organic diseases is the determination of chemical substances in body fluids. For example, to determine lactate dehydrogenase (LDH) in serum in the case of blood or liver diseases or cardiac infraction, reagents are added to the sample of body fluid and the resulting changes are determined photometrically. Such determination is based on the principle that the lactate dehydrogenase enzyme catalyzes the hydrogen transfer reaction: EQU pyruvate+NADH+H.sup.+ .revreaction.lactate+NAD.sup.+
wherein the equilibrium is shifted to the side of the lactate and NAD (nioctinamide-adenine dinucleotide). The LDH activity is determined from the rate of decrease of NADH (reduced nioctinamide-adenine dinucleotide) caused by such reaction. NADH can be easily determined because of its absorption at 366, 340 or 334 nm.
Implementation of such methods involves mixing and pipetting processes that require extreme accuracy and are rather time-consuming. In addition, some of the reagents have to be prepared fresh from a parent solution before use. The reactions are furthermore influenced by a number of factors, e.g., the effects of the reagents, impurities, etc.